Slow debugging in codeblock is this normal! The debugger code itself is very slow, all windows: watch, dissasemble, register, etc use a complete update of their area, even if they only need to update one symbol. Moreover, the used wxwidget has fatal flaws, which, after a while, practically lead to the debugger freezing. That is, at first the debugger works quickly, but then, it starts to slow down significantly due to errors in wxwidget.
Wxwidget has different functions that work in the same way or with minimal differences, replacing resource-intensive functions with less resource-intensive ones will lead to less memory leaks and stabilize the situation.